Fix elf/tst-env-setuid[-static] if test needs to be rerun.

If /tmp is mounted nosuid and make xcheck is run,
then tst-env-setuid fails UNSUPPORTED with "SGID failed: GID and EGID match"
and /var/tmp/tst-sonamemove-runmod1.so.profile is created.

If you then try to rerun the test with a suid mounted test-dir
(the SGID binary is created in test-dir which defaults to /tmp)
with something like that:
make tst-env-setuid-ENV="TMPDIR=..." t=elf/tst-env-setuid test
the test fails as the LD_PROFILE output file is still available
from the previous run.

Thus this patch removes the LD_PROFILE output file in parent
before spawning the SGID binary.

Even if LD_PROFILE is not supported anymore in static binaries,
use a different library and thus output file for tst-env-setuid
and tst-env-setuid-static in order to not interfere if both
tests are run in parallel.

Furthermore the checks in test_child are now more verbose.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

3 files changed, 42 insertions, 6 deletions

diff --git a/elf/Makefile b/elf/Makefile
index afec7be..87aac92 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -3015,6 +3015,7 @@ tst-env-setuid-ARGS = -- $(host-test-program-cmd)
 
 # Reuse a module with a SONAME, to specific as the LD_PROFILE.
 $(objpfx)tst-env-setuid: $(objpfx)tst-sonamemove-runmod2.so
+$(objpfx)tst-env-setuid-static.out: $(objpfx)tst-sonamemove-runmod1.so
 
 # The object tst-nodeps1-mod.so has no explicit dependencies on libc.so.
 $(objpfx)tst-nodeps1-mod.so: $(objpfx)tst-nodeps1-mod.os
diff --git a/elf/tst-env-setuid-static.c b/elf/tst-env-setuid-static.c
index 0d88ae8..162d916 100644
--- a/elf/tst-env-setuid-static.c
+++ b/elf/tst-env-setuid-static.c
@@ -1 +1,2 @@
+#define PROFILE_LIB      "tst-sonamemove-runmod1.so"
 #include "tst-env-setuid.c"
diff --git a/elf/tst-env-setuid.c b/elf/tst-env-setuid.c
index 9fa591a..b4f0e54 100644
--- a/elf/tst-env-setuid.c
+++ b/elf/tst-env-setuid.c
@@ -36,7 +36,9 @@ static char SETGID_CHILD[] = "setgid-child";
 #define UNFILTERED_VALUE "some-unfiltered-value"
 /* It assumes no other programs is being profile with a library with same
    SONAME using the default folder.  */
-#define PROFILE_LIB      "tst-sonamemove-runmod2.so"
+#ifndef PROFILE_LIB
+# define PROFILE_LIB      "tst-sonamemove-runmod2.so"
+#endif
 
 struct envvar_t
 {
@@ -53,7 +55,7 @@ static const struct envvar_t filtered_envvars[] =
   { "LD_HWCAP_MASK",           FILTERED_VALUE },
   { "LD_LIBRARY_PATH",         FILTERED_VALUE },
   { "LD_PRELOAD",              FILTERED_VALUE },
-  { "LD_PROFILE",              "tst-sonamemove-runmod2.so" },
+  { "LD_PROFILE",              PROFILE_LIB },
   { "MALLOC_ARENA_MAX",        FILTERED_VALUE },
   { "MALLOC_PERTURB_",         FILTERED_VALUE },
   { "MALLOC_TRACE",            FILTERED_VALUE },
@@ -83,7 +85,12 @@ test_child (void)
        e++)
     {
       const char *env = getenv (e->env);
-      ret |= env != NULL;
+      if (env != NULL)
+	{
+	  printf ("FAIL: filtered environment variable is not NULL: %s=%s\n",
+		  e->env, env);
+	  ret = 1;
+	}
     }
 
   for (const struct envvar_t *e = unfiltered_envvars;
@@ -91,13 +98,30 @@ test_child (void)
        e++)
     {
       const char *env = getenv (e->env);
-      ret |= !(env != NULL && strcmp (env, e->value) == 0);
+      if (!(env != NULL && strcmp (env, e->value) == 0))
+	{
+	  if (env == NULL)
+	    printf ("FAIL: unfiltered environment variable %s is NULL\n",
+		    e->env);
+	  else
+	    printf ("FAIL: unfiltered environment variable %s=%s != %s\n",
+		    e->env, env, e->value);
+
+	  ret = 1;
+	}
     }
 
-  /* Also check if no profile file was created.  */
+  /* Also check if no profile file was created.
+     The parent sets LD_DEBUG_OUTPUT="/tmp/some-file"
+     which should be filtered.  Then it falls back to "/var/tmp".
+     Note: LD_PROFILE is not supported for static binaries.  */
   {
     char *profilepath = xasprintf ("/var/tmp/%s.profile", PROFILE_LIB);
-    ret |= !access (profilepath, R_OK);
+    if (!access (profilepath, R_OK))
+      {
+	printf ("FAIL: LD_PROFILE file at %s was created!\n", profilepath);
+	ret = 1;
+      }
     free (profilepath);
   }
 
@@ -141,6 +165,16 @@ do_test (int argc, char **argv)
 	   e++)
 	setenv (e->env, e->value, 1);
 
+      /* Ensure that the profile output does not exist from a previous run
+	 (e.g. if test_dir, which defaults to /tmp, is mounted nosuid.)
+	 Note: support_capture_subprogram_self_sgid creates the SGID binary
+	 in test_dir.  */
+      {
+	char *profilepath = xasprintf ("/var/tmp/%s.profile", PROFILE_LIB);
+	unlink (profilepath);
+	free (profilepath);
+      }
+
       int status = support_capture_subprogram_self_sgid (SETGID_CHILD);
 
       if (WEXITSTATUS (status) == EXIT_UNSUPPORTED)